Wait, is mycelium poisonous? Mycelium is not poisonous, but we definitely do not recommend eating the substrate. By Eileen Morée|2020-06-13T10:40:46+00:00June 13th, 2020|General| Share This Story, Choose Your Platform! FacebookTwitterRedditLinkedInTumblrPinterestVkEmail About the Author: Eileen Morée